“We study the self to forget the self,” wrote Zen master Dogen, “and when we forget the self the world becomes magical.” As we become familiar with our habits of mind, Dogen implies, their power to filter perception diminishes. A similar insight applies to creativity in the arts and sciences. Marcel Duchamp admired Francis Picabia because he “had the gift of total forgetting which enabled him to launch into new paintings without being influenced by the memory of preceding ones.” “What one seems to want in art,” wrote Elizabeth Bishop, is “a self-forgetful, perfectly useless concentration.” She was thinking of the young Charles Darwin, how his “heroic observations” appeared to be followed by “a sudden relaxation, a forgetful phase” in which he slides “giddily off into the unknown.”

Forgetting can appear as a political ideal as well. South Africa’s Truth and Reconciliation Commission proceeded in a way that replicated the sequence of Dogen’s aphorism: study first, then forget; uncover the truth, then let go. As Archbishop Desmond Tutu once explained, the Commission chose the path of restorative, rather than retributive, justice, and at its end—after attention has been paid—restorative justice offers amnesty, judicial forgetfulness. (The book will touch on the South African case but in fact it does so in order to explore the possibility of American “truth and reconciliation,” particularly in regard to the history of racial violence.)

Such modern valuations of forgetfulness have ancient antecedents. In western mythology, Mnemosyne, the Mother of the Muses, is not simply Memory for even as she helps humankind to recall the Golden Age she helps them to forget the Age of Iron they now must occupy. "For though a man have sorrow and grief…," wrote Hesiod, "yet, when a singer…chants the glorious deeds of men of old and the blessed gods who inhabit Olympus, at once he forgets his heaviness and remembers not his sorrows at all.”

Absent the blessings of forgetfulness we would all be like Borges's monstrous figure, Funes, who was unable to forget even the smallest details of his days so that a tree at 3:06 p.m. with the light just so on its leaves stayed with him as wholly distinct from the same tree two minutes later shaded by a cloud. "He was ... almost incapable of general, platonic ideas...," Borges’s narrator remarks, for "to think is to forget a difference, to generalize, to abstract."

"Tree" is not the only abstraction that comes into being through the twinned powers of memory and erasure. Take the idea of nationhood: in the late nineteenth century, the French philologist Ernest Renan gave a lecture–"What Is a Nation?"–arguing that even when there is a shared and rich legacy of memories, "the essence of a nation is that all its individuals have many things in common, and also that everybody has forgotten many things.” Even someone as firmly grounded in empirical science as Sir Francis Crick can find himself theorizing in terms that echo both Hesiod and Borges: in a 1983 essay in Nature, Crick and a friend proposed that "We dream in order to forget." Each of our days is so filled with particularity, we are so swamped with sensory detail, that the mind needs a way to winnow the trivial from the essential, and dreaming, Cricked argued, does just that.

From the age of Hesiod to present day neuroscience, the literature on forgetting and forgetfulness is so vast as to defy any summary approach or single line of argument. A Primer for Forgetting consequently takes the form of a series of brief, layered explorations drawn from many sources (myth, history, politics, the arts, psychology, science...) and arranged juxtapositionally around the core theme of forgetting.

Many ancillary ideas arise in passing, of course. For example, in the Phaedrus Plato famously argues that the art of writing damages memory: once philosophers and bards begin to rely on written records, calling things to mind "no longer from within themselves, but by means of external marks," they will necessarily abandon the ancient memory arts by which their wisdom had long been preserved and transmitted. Modern work on the oral tradition has shown, however, that the opposite can also be the case: writing damages forgetfulness. An oral society, wrote Walter Ong, keeps itself "in equilibrium ... by sloughing off memories which no longer have present relevance." As soon writing freezes memory, the intercessions of forgetting disappear and the balance is lost.

Oddly, then, text-based societies have had to cobble together new ways to preserve the virtues of forgetting. Take the idea of a “statute of limitations.” In English law, customary rights cannot be challenged if they’re found to have existed from “time out of memory.” A nineteenth-century ruling, for example, protected an “ancient and laudable” horse race from litigation because it had been run regularly “from time whereof the memory of man runneth not to the contrary.” Amusingly, that time even has a fixed date in English law: the Statute of Westminster the First sets the outer limit of “legal memory” at the beginning of the reign of Richard I. Everything before that belongs to “time immemorial” and is safeguarded by the very fact of its forgotten origins.

In all these cases, both what we remember and what we forget contribute to our sense of who we are, collectively and individually. Most typically, identity is assumed to depend on memory and consequently changes of identity call for an art of forgetting. This is a theme that was well developed in nineteenth-century New England where writers like Emerson, Thoreau, and Hawthorne, eager to abandon European roots and develop a native literature, wrote stirringly in favor of erasing the past. "The Atlantic is a Lethean stream, in our passage over which we have had an opportunity to forget the Old World and its institutions," wrote Thoreau in a typical passage. "If we do not succeed this time, there is perhaps one more chance for the race..., and that is in the Lethe of the Pacific, which is three times as wide."

No one action of the Lethean stream is the focus of the book, however. A Primer for Forgetting keeps returning to certain areas of interest—especially to myth, creativity, and trauma (both historical and personal)—and the work as a whole has for its focus the simple claim that forgetting can be as valuable as remembering. The form, however, lies closer to fiction or drama than to the defense of a thesis; the genre is the literary, not the academic, essay, the desired end being less a matter of guiding the reader to known conclusions than of creating a provoking and invitational ground from which a reader’s own reflections may freely arise.

A Primer for Forgetting is under contract with publisher Farrar, Straus & Giroux.